Low-voltage pentacene photodetector based on a vertical transistor configuration
06 Jan 2015-Acta Physica Sinica (Acta Physica Sinica, Chinese Physical Society and Institute of Physics, Chinese Academy of Sciences)-Vol. 64, Iss: 10, pp 108503
TL;DR: In this paper, a low-voltage pentacene photodetector ITO/Pentacene(80nm)/Al(15nm) was proposed, which exhibited good p-type transistor behavior and lowvoltage-controlling performance.
Abstract: Due to the excellent characteristics in field-effect transistors and its high absorption coefficient in the visible region, pentacene has been widely used in phototransistors. The channel length of the vertical transistor could be designed very short to nanometers. In this way, the device performances and its working frequency can be effectively improved, and the energy consumption can be reduced simultaneously. In this paper, we fabricated a kind of low-voltage pentacene photodetector ITO(S)/Pentacene/Al(G)/Pentacene/Au(D), basing on the vertical transistor configuration. The threshold voltage and “on/off” current ratio were -0.9 V and 104 at a low working-voltage of -3 V, respectively. The pentacene photodetector ITO/Pentacene(80nm)/Al(15nm)/Pentacene (80nm)/Au exhibited good p-type transistor behavior and low-voltage-controlling performance. The photosensitivity and responsivity varied with incident monochromatic light from 350 nm to 750 nm, and the photosensitivity peak of 308 was obtained at 350 nm with a responsivity of 219 mA/W, which is even higher than the standard Si-based photodetector under 350 nm incident light. Therefore, it provides an easy way to get a high sensitivity all-organic photodetector working at low voltages.
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TL;DR: The research progress in each type of organic photomultiplication photodetectors based on the trap assisted carrier tunneling effect is reviewed in detail and the prospects of future research into these devices are discussed.
Abstract: Organic photomultiplication photodetectors have attracted considerable research interest due to their extremely high external quantum efficiency and corresponding high detectivity. Significant progress has been made in the aspects of their structural design and performance improvement in the past few years. There are two types of organic photomultiplication photodetectors, which are made of organic small molecular compounds and polymers. In this paper, the research progress in each type of organic photomultiplication photodetectors based on the trap assisted carrier tunneling effect is reviewed in detail. In addition, other mechanisms for the photomultiplication processes in organic devices are introduced. Finally, the paper is summarized and the prospects of future research into organic photomultiplication photodetectors are discussed.
45 citations
TL;DR: In this paper, a series of highly sensitive polymer photodetectors (PPDs) was fabricated with P3HT :PBDT-TS1 x :PC BM as the active layers, where x represents the PBDT −TS1 doping weight ratio in donors.
Abstract: A series of highly sensitive polymer photodetectors (PPDs) was fabricated with P3HT :PBDT-TS1 x :PC BM as the active layers, where x represents the PBDT-TS1 doping weight ratio in donors. The response range of PPDs can cover from the UV to near-infrared regions by adjusting the PBDT-TS1 doping weight ratio. The best external quantum efficiency (EQE) values of ternary PPDs with P3HT:PBDT-TS1:PC BM (50:50:1 wt/wt/wt) as the active layers reach 830%, 720%, and 330% under 390-, 625-, and 760-nm light illumination and −10 V bias, respectively. The large EQE values indicate that the photodetectors utilise photomultiplication (PM). The working mechanism of PM-type PPDs can be attributed to interfacial trap-assisted hole tunnelling injection from the external circuit under light illumination. The calculated optical field and photogenerated electron volume density in the active layers can well explain the EQE spectral shape as a function of the PBDT-TS1 doping weight ratio in donors.
11 citations
TL;DR: In this paper, the authors presented short channel field effect phototransistors (FEpTs) by combing the QDs with the vertical architecture for the first time, and these devices exhibit excellent performances in ultrahigh R of 1 × 105 A W−1, D* of 1.6 × 1013 Jones, effective quantum efficiency of 2.6× 107% at low operating voltage of ±4 V under room temperature, and they strongly depend on channel length.
Abstract: Quantum dot (QD) devices have been studied extensively as a significant platform for optoelectronic applications and photodetection, but the high efficient conversion from light to current requires high operating voltages, and has become a roadblock in a wide range of on chip applications. The main challenges rely on promoting light absorption and transportation efficiency, which occur in the same place—the channel. Here, the authors present short channel (SC) field effect phototransistors (FEpTs) by combing the QDs with the vertical architecture for the first time. These devices exhibit excellent performances in ultrahigh R of 1 × 105 A W−1, D* of 1.6 × 1013 Jones, effective quantum efficiency of 2.6 × 107% at low operating voltage of ±4 V under room temperature, and they strongly depend on channel length. It is found there was an optimal L to obtain high performances, due to the two roles of channel, light harvesting, and electric transportation, which give the negative and positive contributions to photocurrent, respectively. These SC QVFEpTs exhibit a great application in photodetection, from visible to infrared, moreover, the all-solution fabricating process and lateral detection (determined by vertical architecture) provide a convenient pathway for low cost, integrated circuit architectural compatibility.
11 citations